/**
  * Checks whether the state of the filter collection is clean.
  *
  * @return boolean True, if the filter collection is clean.
  */
 public function isFiltersStateClean()
 {
     return null === $this->filterCollection || $this->filterCollection->isClean();
 }
 public function testSetFiltersStateDirty()
 {
     $this->filterCollection->setFiltersStateDirty();
     $this->assertFalse($this->filterCollection->isClean());
 }